Luis Sinisterra has now scored three goals in his past five games for Leeds
Vardy slotted home a cool finish in the 80th minute from James Maddison's pass and the former England striker then thought he had won it when converting from close range, but it was ruled out for offside.
Colombian winger Luis Sinisterra opened the scoring in the first half with a header at the back post from Jack Harrison's pin-point cross, but the hosts could not hold on.
The draw leaves Leicester firmly in trouble, only out of the bottom three on goal difference, and they will drop into the relegation places if Everton avoid defeat against Newcastle on Thursday, while Leeds are a further point ahead.
The Foxes thought they had taken the lead inside the opening 10 minutes but Youri Tielemans' thunderous finish was ruled out by VAR as Boubacary Soumare was ruled to be offside in the build-up.
Dean Smith's side were chasing the game in the second half but were frustrated by Leeds goalkeeper Illan Meslier, who twice denied Kelechi Iheanacho, before Vardy popped with the leveller.
Leeds should have won it in the final minute but striker Patrick Bamford somehow scuffed wide from close range from a couple of yards out.
This was a contest between two out-of-form teams who are scrapping to preserve their top-flight status and both sides left Elland Road having to be content with a point.
Roared on by raucous home crowd, Leeds outmuscled their opponents for much of the game by snapping into tackles and their aggression was evident with four players picking up bookings.
Sinisterra put them in front with a well-taken header but they failed to push forward in the second period and were punished by Vardy.
The result ended a sequence of three consecutive defeats for Leeds, but Javi Gracia's men missed out on going four points clear of the drop zone.
Leeds went in search of the winner in injury time and came agonisingly close but Marc Roca's flicked header was superbly kept out by an acrobatic save from Daniel Iversen, before Bamford's glaring miss.
Leicester picked up a pivotal win over Wolves at the weekend - their first in nine games - but they failed to back up that showing in West Yorkshire.
They struggled to create chances in the final third and it took until Kelechi Iheanacho's drive from long range in the 73rd minute for their first shot on target.
Leeds keeper Meslier also kept out a dinked effort from the Nigerian striker but could do nothing about veteran front man Vardy calmly stroking in his first goal since December.
Leicester's lack of cutting edge in front of goal is not helped by a porous defence that has conceded in 18 consecutive games, and they are the only side in Europe's top five leagues without a clean sheet since the World Cup.
Leeds next face Bournemouth on Sunday while Leicester host 18th-placed Everton the following day.
-- Courtesy of BBC Sport